package com.atguigu.springcloud.lb;


import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

//@Component
@Slf4j
public class MyLB implements LoadBalancer {

    private AtomicInteger atomicInteger = new AtomicInteger(0);


    private final int getAndIncrement(){
        int current;
        int next;
        do{
            current = this.atomicInteger.get();
            next = current >= Integer.MAX_VALUE ? 0 : current + 1;
        }while (!this.atomicInteger.compareAndSet(current,next));
        log.info("next:{}",next);
        return next;
    }


    @Override
    public ServiceInstance instance(List<ServiceInstance> serviceInstances) {
        int count = getAndIncrement();
        int index  = count % serviceInstances.size();
        return serviceInstances.get(index);
    }
}
